A Massachusetts smoking ban in restaurants, bars, and other workplaces has led to almost 600 fewer annual coronary deaths, according to a new report from the state Department of Public Health and the Harvard School of Public Health.

The Boston Globe reported Nov. 12 that the report found steep declines in the number of heart-attack deaths since the state adopted the smoking ban, with a 30-percent decrease in deaths between 2003 and 2006.

The authors of the report compared communities that adopted smoking ban with those without smoking bans and estimated that 577 fewer people died each year from heart attacks as a direct result of the ban.

"This is the strongest study yet done of the effect of smoking bans on heart attacks," said Michael Siegel, who is a tobacco-control specialist at Boston University School of Public Health. "You can no longer argue that these declines would have occurred simply due to medical treatment."

The authors said that advances in treatment of heart attacks were not responsible for the smaller number of deaths.

The Henry Ford Hospital in Michigan presented similar findings this week at the American Heart Association's annual conference, with researchers estimating that the number of heart-attack patients admitted to hospitals in the state would drop by 12 percent in the first year of a statewide smoking ban.

"People have assumed that the only benefit we will be able to measure of a smoking ban is long-term benefits," said John Auerbach, Massachusetts' public-health commissioner. "This study demonstrates a real connection between smoking bans and short-term improvement in health outcomes."